I upgraded yesterday as well. I can confirm other reports: while the increase in speed was expected (map redraws, slacker caching, etc), what is surprising is the increase in signal strength. I don't know if the upgrade included new/better tuned antennas, or if the new radio has better shielding/is less susceptible to RFI, or if the cables to the antennas have less loss.. whatever the reason, signal quality is improved. Driving in the DC metro area, between Rockville and Tysons, I had 5 bars the entire time. It wasn't until I got into Vienna and secondary roads that it went down to 4 bars. At my home I now have 3 whereas previously I had 1. Now of course this could simply be a UI game, what really matters is the db level which we don't have access to. But it does seem to be improved.
Definitely worth the $500 imho. I wonder if the new radio supports AT&T LTE band 30 in the US?